My personal view when someone says I have a villa or townhouse, it's the same thing where it could be single or double story and both will have a mini yard. We don't use the term terrace or bungalow here in Sydney metro or anywhere else I have been to within Australia. A Terrace to me is the courtyard area on a ground floor unit. Some agents may use the term as it may sound appealing and have people curious as to what it is.
The same with unit or apartment, it's the same deal.